Manufacture of coating and impregnating materials.



naar. norte', or rnnnnronfr-earns-Maria, GERMANY.'

'MAN'JFACTRE OE CATING AND IMPREGNATING MATERIALS.

'i ,enanas No Drawing.

To '/Z whom it 'may Con/icm.'

le it known that l, (hun. Roan-1, chemist and doctor ott philosophy, acitizen of the German lCnipire, and resident of Frankforton-the-ilain,Gerin-any, (with the post-elfico address Sommeringstrasse 30,) haveinvent` ed new and useful improvements in the lllanuiacture of Coatingand impregnating li'laterials, or which the following is aspecificationa Materials which are to be used aspirarnishes, coatings orinsulations and are ha ille to contact'with industrialeiiluents, suchi'or example, as waste gases, chemically inl` pregnated Wale and thelike and active constitueuts of the soil, vfulfil their protectiveVfunction more conipletely and longer the more cheniieall." stable theyare originally to the attack ol dilute acids and alkalis as u'rll asgaseous substances dissolved in water. Natural asphalt and solidconstituents ot tar are suilahle 'for the aforesaid purposes only in sofar as their general chemical cha acteraueets the requirements. For theorig-in and descent ot these substances determine that more or less oftheir constituents are liable to the solvent or destructivo el'ect ofthe agents in question, whereby such con. uents are removed hy tlnWntcr.llfhen. ihere'lore, such chemically destructilile emistituents arepresent in varnishes made Ylroui asphalt or tar.I they are Washed awayby the water from the covered surfaces leavingA an imperfect protectivelayer.

The 'folloii'ing observation has been made: When a rarnish made from taror asphalt is subjected to a water of the kind in question containingactive substances to an eX- Atent short of that which would destroy theu'hole uniss, but only injure it by renieriug certain parts,thereren'iain residual sul)- slanees which when airain made up into a varnishby' iur-.ans ol a suitable solvent are able to resist i'iutheixatiaclroll the saine water. this manner behave the residues oli coatings whichhave been szihiecteal on pipes ai 'lr surfaces olf tanks lo gradualdestruction, sometimes by acid iuarshy grounfrl, somt-.i hues by slrougalkaline conditions, and cron. hy water rif-h iu carbon dioxid andoxygen.

'the present invention based ou the lnvestie'al'iou ot the aforesaidobservation.

clordiug lo the invention natural asphalt, asphalt puriiied by knownspecial processes, solid residuos from the distillation oi'hitumi-Specification of Letters Patent.

Patented May 5, B214.

Application led January 29, 1913. Serial No. 745,018.

nous and fossilized materials, or tar pitch.

of any kind, is first powdered as finely as possible. rlhis pulverizingoperation Inust,t; it necessary, he carried out in a cooled cham# f ber,il materials ot such low melting point are und-er treatment that theywould *softenA and agglomerato under the influence of'a' raisedtemperature so that they could not be ground. The linely ground dustybitu minous substance is left in Contact with acid or an alkalineliquid, or with each kin succession, While constantly stirred, orWhile," air is blown through, the treatment lasting for days, Weeks ormonths. The action. of the acid or. alkaline` substance on the powderedmaterial must oeeul#A at temperatures below the melting point of themateria-l, otherwise the finest particles would become mechanicallyunited in a mass impenetrable hy the active liquid and would remain forthe most partV unchanged bythe chemical action which is vthe object of'the' operation. Generally speaking temperatures between 2:5 and GGO C.are best for the pur.-` pose in question accordingly as the sepa)-` rateconstituents of the material show notendeney to agglomerato or fusetogether within these limits.

'Correspondingly'with the degree of resistance which the coating orimpregnating material is to have in its suhsequentpraotical application,the degres of concentra` tion of' the acid or alkali Which is used inthe preliminary process for providing per# nianence may be varied, thusmore orlessv dilute hydrochloric acid, nit 'ic acid and 'suliuricncidmay serve the purpose indicated. The concentration of the acid isdiminished at first by doeompositious which, according to the acidselected, are accompanied by considerable evolution of gas or by theforma# tion of nitro-substaneesin geiieral the .subsequent protection,of the varnish against the action of dilute acidsl achieved it the.finely powdered'loituinin nous substance is lett in Contact for two'months at about Q50 U. with hydrochloric acid ot' 'specific gravity1.1525, or with sultur*l acid ot' specific gravity 1.1.16, or withnitric acid ot' specific gravity 1.054. :The re sistance ol the organicbasis is only invcreased when the treatmentduring the said` articularadvantage vthat the .bituminous- I

